The present invention relates to a door check device for installation between a motor vehicle body and a motor vehicle door.
A known door check device is produced by Ed. Scharwachter GmbH and Co. KG. in Europe and North America and is disclosed, for example, in U.S. Pat. No. 4,997,221 and in U.S. Pat. No. 5,026,103, the entire disclosures of both of which are incorporated herein by this reference. Referring to FIGS. 1-2 of the present application, such door checks conventionally utilize an xe2x80x9cSxe2x80x9d or xe2x80x9cCxe2x80x9d shaped torsion spring structure, generally indicated at 11, to bias a cylindrical roller 15 rotatably mounted to one of the end portions of the spring into engagement with a link member 21. The other end portion of the torsion spring structure is usually fixed. As the link member 21 moves relative to the roller 15 during door opening and closing movements, the roller rides up and over one of the protrusions 57. The torsion spring structure torsionally deflects at the center section 13 thereof to accommodate this movement. This torsional deflection is stored as energy and causes the spring structure to bias the roller 21 into the detent 17 defined between the protrusions 57 after the roller rides over the top of one of the protrusions 57. An analysis of the torsion spring structure 11 shows that most of the deflection energy built up in the spring structure 11 is generated within the center section 13 thereof. As a result, the cross sectional area must be sufficient enough to resist deflection as the roller is urged up the sloped surface of one of the protrusions 57 to maintain the roller 21 within the detent 17. This retains the door in its checked position until sufficient force is applied to ride the roller 21 up and over one of the protrusions 57 and out of detent 17, thus freeing the door for unchecked swinging movement. Further, the cross sectional area of the center section must be sufficient enough to withstand repeated torsional deflections over the life of the motor vehicle in which it is installed without fatiguing.
As a result of the overall efforts in the vehicle industry to reduce vehicle costs and weights, vehicle part manufacturers are continually trying to reduce the costs and weights of their parts. With respect to the present subject matter, there is a need in the art for a door check device that either performs comparably to the type described above but at a lower weight and cost or that performs better than the type described above without increased cost or weight.
It is therefore an object of the present invention to meet the above-described need. To achieve this object, the present invention provides a door check device for installation between a motor vehicle body and a motor vehicle door that swings in opposing opening and closing directions relative to the vehicle body. The device comprises a first mounting structure and a second mounting structure. The first mounting structure is constructed and arranged to be mounted on one of the vehicle door and the vehicle body and the second mounting structure is constructed and arranged to be mounted on the other of the vehicle door and the vehicle body such that the first and second mounting structures move relative to one another as the door is swung in the opposing opening and closing directions thereof relative to the vehicle body. The device also comprises first and second spaced apart cooperating structures and a link member having a detent provided on an intermediate portion thereof. In addition, the invention encompasses having a single pair of detents on opposing sides of the link member, two or more of such pairs of detents to provide for more than one checked position, or two or more detents on only one side of the link member to provide for more than one checked position. The link member is received between the cooperating structures with the cooperating structures engaging opposing sides of the link member. The link member is carried by the first mounting structure and cooperating structures are carried by the second mounting structure such that the link member and the cooperating structures move relative to one another as the door is swung in the opposing opening and closing directions thereof relative to the vehicle body.
A spring structure is carried by the second mounting structure. The spring structure has first and second resilient torsionally deflectable biasing portions spaced apart and torsionally isolated from one another such that transmission of torsional stress between the torsionally deflectable portions is substantially prevented. The first cooperating structure is connected to the first biasing portion and the second cooperating structure is connected to the second biasing portion such that (a) the biasing portions apply biasing forces to bias the two cooperating structures into engagement with opposing sides of the link member and (b) movement of the cooperating structures generally apart from one another individually torsionally deflects the first and second biasing portions so as to individually increase torsional stress within the biasing portions and thereby increase the respective biasing forces applied by the biasing portions.
The first and second cooperating structures are constructed and arranged such that when the vehicle door is swung to a checked position with respect to the vehicle body, one of the cooperating structures is received within the detent in a cooperating relationship to maintain the vehicle door at the checked position until a force is applied to the door sufficient to cause the link member to move relative to the cooperating structures so as to urge the cooperating structures generally apart from one another against the biasing of the torsionally deflectable biasing portions and move the one cooperating structure out of the detent.
Because the invention uses two torsionally deflectable biasing portions instead of only one as in the case of the prior art, comparing a prior art door check device and a door check device of the present invention wherein each device has the same diameter spring structure and detent(s) of the same geometry and depth, the device of the present invention will offer almost twice as much resistance to movement of the door from the checked position. Further, it would also be possible to design a door check device of the invention that offers the same amount of resistance to movement of the door panel with the same diameter spring structure by increasing the depth of the detent(s), thus distributing the force over two biasing portions so that the fatigue life of the spring structure is extended. Alternatively, it would be possible to produce a door check device capable of offering the same amount of resistance to movement of the door panel from the checked position as the prior art door check assemblies discussed above, but with a smaller and lighter spring structure.
These and other objects, features, and advantages of this invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, the principles of this invention